For example, a vehicle door structure disclosed in Patent Literature 1 has been known as a vehicle door structure. The vehicle door structure disclosed in Patent Literature 1 has a first door panel and a second door panel, the first door panel is configured to be slidable with respect to a vehicle body and the second door panel, and at the same time, the second door panel is configured to be swingable with respect to the vehicle body. Further, in the vehicle door structure according to the related art, in order to improve stability for slide opening/closing of a slide-openable door panel, when the slide opening/closing of the slide-openable door panel is performed, the slide-openable door panel is supported by a vehicle, and when the slide-openable door panel is fully opened, the supporting of the slide-openable door panel by the vehicle is released.